The case exposed glaring problems in forensic science and what happens when biases taint an investigation.
“The eyes are not responsible when the mind does the seeing.” — Publilius Syrus
Fear compelled her heart to build up to a terrifying and deadly 100 mph crescendo…
Shallow, rapid half gasps emanated from the 62-year-old widow as her skin turned a pallid blue… the Monster garroting her with steel wire from her kitchen.
Slow… Fast! … Slow… Fast! … Slow.
The hands of the Monster were possessed by the brute strength of a seasoned bare-knuckle boxer and the dexterity of an accomplished concert pianist — completely enveloped by fury spawned in the latter circles of hell.
Fast! (and sustained as the widow squirmed, trying in vain to fight back)
Lieselotte Schlenger expired on the floor of her beloved kitchen that day in 1993. Her death marked the opening of Pandora’s box that was the Phantom of Heilbronn case — though no one would realize this for another eight years.
The Phantom of Heilbronn case exposed glaring problems in forensic science and what happens when universal cognitive biases taint an investigation — all wrapped up in a tale that rivals the best crime fiction.
Like a malevolent Proteus in Greek mythology, the Phantom was a ghostly, shapeshifting boogeyman (or woman) terrorizing the populations of three countries. The Phantom changed and became lesser-known when (s)he was pursued by law enforcement.
It would take more than mere mortals to catch this Monster. Law enforcement would have to use the best of science at the time, combined with questioning their own cognitive biases and the deepest logical connections between both forensic and behavioral evidence.
That last part gets even harder when one of your own is assassinated while eating and the alt-right hurls itself — Nazi salutes first — into your investigation.
The Scene and the Intervening Years
The day before her murder, Schlenger emptied nearly all cash from her savings account — something very unusual for the normally frugal widow. Police found none of the money in her home.
Though 1993 did not yet see the wide use of DNA, officers did manage to take a sample from Schlenger’s house — that of an unknown female — from Schlenger’s coffee cup. With that unfortunate lack of proper technology, the sample was cataloged and forgotten about.
The case soon went cold.
Joseph Walzenbach: March 26, 2001
Joseph Walzenbach was a 61-year-old antique dealer from the town of Freiburg (population 230,241) — almost 300 km and three hours from the first scene eight years earlier at Idar-Obserstein.
He had been savagely beaten with an undetermined blunt object and strangled with a belt.
Like the Schlenger case, cash had been taken from the Walzenbach crime scheme. The same unknown female DNA found at the Schlenger scene was found on a drawer at the Walzenbach scene.
These clues gave the investigators the idea of a murderous female robber. That is until they realized their series — this crime spree — was far from over.
Gerolstein, Germany — the Playground and the Junkie’s Needle: October 2001
On October 24, 2001, a child stepped on a syringe containing heroin near a playground in the city of Gerolstein, Germany (population 7520, Gerolstein is about 363km — a little over four hours — north of Freiburg).
Heroin was a big problem in this area of Germany at the time, so the police cataloged the syringe and did little else with it — thinking it was yet another faceless junkie. This upset local parents to the point that they demanded a DNA test on the syringe.
The test ended up finding the same unknown female DNA on the syringe that was found at the Schlenger and Walzenbach crime scenes.
Police started building their profile from this point: a female double murderer who engages in criminality to fund her habit.
Sounds simple, right? Logical? Predictable? Not so much. There is ZERO consistency to the Phantom’s behavior so far. Which makes it tough. A profile may be useful if it updates with new information — like anything else. Bayesian reasoning is essential here.
Still, this story gets demonstrably weirder in every conceivable way.
DNA Everywhere and not a Soul to Pin it on
After the syringe at the Gerolstein playground, police began noticing the same unknown female DNA everywhere.
Our Phantom DNA showed up in car and motorcycle thefts; “settling of scores” in Germany (more on this below), and at a dozen burglaries and attempted burglaries in Austria.
She even took a bite out of a cookie during a breaking and entering in Budenheim, Germany (population 8534, and 86.9km or one hour and ten minutes from the 1993 Schlenger crime scene at Idar-Oberstein).
Like the chameleon-like Proteus, the Phantom of Heilbronn seemed to shed her skin, face, and every shape as police gave chase. She thus earned the nickname, “the Woman Without a Face.”
Still, we have not even begun to see the truth, compellingly weird in this case.
The Vietnamese Precious Gemstone Traders: 2004
Arbois, France (population 3407 and about 500km, or five and a half hours, south of Gerolstein) was rocked to its core when a group of Vietnamese precious gemstone traders was brutally attacked by a gang of robbers.
The robbers made off with about 3,000 Euros, jewelry, and gold bullion.
The most interesting find — however — was a reproduction of a Beretta FS92 pistol. Once ran through both the French and German databases, the DNA of our unknown female master criminal was found on it.
All four male robbers were arrested soon after the heist. None copped to the involvement of a female accomplice, even while under intense and protracted interrogation by French and German authorities.
If you’re keeping track so far, that’s three countries our murderous, female, waif-like, junkie, cookie-loving, criminal mastermind has terrorized. She has also apparently scared several hardened street toughs into absolute silence about her existence.
And she’s far from done.
A Fuller Scope of the Phantom
Once the police had a bead on the Phantom, they started testing DNA from old crimes. The results shocked them; from May 1993 to October 2008, the Phantom’s DNA was found in 30 separate crime scenes in Germany and Austria.
Her DNA was found at office robberies, home burglaries, supermarket heists, and many shed and campground thefts. Her DNA was even found on a shell casing from the round a man was shot with during a domestic squabble at one of those campgrounds.
This ultimately made investigators a little more conspiratorial in their thinking — they started putting more stock in the Phantom’s law-breaking wiles.
The Austrian authorities were able to find out that the Phantom’s mitochondrial DNA was most common among people from Eastern Europe and Russia. This was new to the Germans as German law only allows for identifying gender from such a sample, nothing else.
Then there was the watershed moment.
A Dead Police Officer: April 25, 2007
Officer Michèle Keisewetter loved the town of Heilbronn (211.9km or over two hours from Idar-Oberstein), population 123,000. Even though she was from a major regional narcotics squad, she rather enjoyed stopping by when she had some free time.
The 25th was a hot day for April in southwest Germany. While eating their lunch, Officer Kiesewetter and her partner Officer Martin Arnold parked their patrol car in the shade of a tree (not far from the lot housing the Phantom of Heilbronn Task Force) at Heilbronn’s Theresienwiese park.
Then a masked force squirmed into the rear of their BMW police cruiser and opened fire on both officers.
Officer Keisewetter was killed instantly from gunshot wounds to the head. She was only 22.
Officer Arnold spent three weeks in a coma after also being shot in the head. He survived but with total amnesia regarding the almost-double homicide. He was 25 at the time.
Both officers’ Heckler & Koch sidearms were missing, as were their handcuffs.
Forensic examination of the scene and the autopsy done on Officer Keisewetter revealed two calibers from two different pistols: a FB Vis .35 and a Tokarev TT-33, the former being of Polish manufacture and the latter of Russian manufacture.
The Phantom’s DNA was found on the BMW’s center console and back seat. It took investigators three months to test the DNA. This fact is ultimately what thrust the entire series of crimes to the dead center of the public eye and compelled the government to throw massive amounts of cash at the problem.
The chameleon Monster of Heilbronn would swallow Officer Keisewetter up — temporarily entangling the fallen hero in another bizarre criminal investigation: that of her own murder (more on this below).
And still, the crescendo of weird in this most bizarre case would not be reached for another two years.
Three Georgians in the Drink: Jan. 2008
It was a frigid day in January when police in Heppenheim (about 99.6km or 1 hour and 10 minutes Northwest of Heilbronn — population 28,000) were called to fish three bodies out of a local body of water.
The three men came from the Eastern European nation of Georgia (Josef Stalin’s birthplace) to buy used cars in Germany. Two of the men had gunshot wounds to the head and the third had been strangled.
Two male suspects were soon arrested while driving a Ford Escort. Investigators found the Phantom’s DNA inside it.
Like the suspects in the Vietnamese precious gemstone trader robbery (roman numeral “V” on this list), despite intense interrogation, none of the suspects copped to the involvement of a female suspect in the triple homicide.
The Phantom must have one hell of an underworld reputation.
The Series Ramps up May 2008 through January 2009
By now, authorities in Germany, Austria, and France were going old school with their police work in launching a massive dragnet in each country to find the Phantom.
Despite every cop in three countries looking for the Phantom, she managed to strike again on May 9. One of the tiniest German states, the Saarland (population almost 1 million), was hit this time when a cleaning lady was brutally attacked and robbed at work. The Phantom got away with several hundred euros.
On October 26, in Heilbronn-Weinsberg, a 45-year old nurse named Diana Pavlenko was found floating in a large pool of water. Her cause of death was “clear” to investigators, but they understandably were not releasing it to have leverage over any suspect they do catch. There was no evidence of a suicide or sex offense having taken place. She had no visible wounds on her. She did have drugs in her system but only at “therapeutic” levels. Her friends reported her history of suicidal ideation and she was going through a divorce.
Still, the only real forensic evidence was the Phantom’s DNA, found in the deceased’s Kia Panda, parked not far from where her body was found.
Soon after Pavlenko’s murder, a gang of Albanian home invaders was arrested in Metz, France. The Phantom’s DNA was found in one of their cars. Yet again, none of the suspects copped to a female accomplice in interrogation.
These new crimes attributed to the Phantom prompted authorities to raise the reward for information to 150,000 euros.
By year’s end, the Phantom struck again. This time it was in Saarbrücken (the capital of the Saarland region, population 178,151) — and this time the Phantom left a witness to her treachery.
The Transsexual Criminal Mastermind
Because the victim of the burglary in Saarbrücken said it was a male perpetrator — and investigators found the Phantom’s DNA at the scene — the police concocted the theory that the Phantom was a woman transitioning into being a man.
Others in law enforcement who were following the series of crimes came to an entirely different (and in the author’s opinion more logical — considering the information they had at the time) explanation: the male was merely another accomplice of the Phantom.
If this were the case, the Phantom would have returned to the crime scene to leave her DNA or gave her mysterious male colleague something saturated with her DNA for him to plant it there as a red herring for the police.
In January 2009, the bounty on the Phantom’s head was upped to 300,000 euros.
The Truth Finally Emerges
In March of 2009, a man was arrested on a charge completely unrelated to any of the cases in the Phantom series.
He was given a DNA test on the spot, and guess what emerges? The Phantom’s DNA. This guy was not transitioning to a woman and had solid alibis for most of the crimes in the series. So, what the hell happened here?
In a word: contamination. The DNA at some 30 crime scenes and six murders in three countries belonged to a woman who worked at the south German firm that manufactures all the cotton swabs investigators in the tri-country area use for DNA collection. There never was a master criminal Phantom of Heilbronn.
Saarbrücken police came to the same conclusion independently but at the same time as their counterparts in other regions of Germany, France, and Austria. The Phantom’s DNA was found on a DNA sample meant to be used as a comparison to the DNA of a severely burnt asylum seeker found in 2002.
The only way the Phantom’s DNA could have ended up there was through contamination. Saarbrücken police would continue to find the Phantom’s DNA on unused swabs — which unequivocally proves the same thing.
Investigators allegedly had an idea it was contamination as early as one year before the March 2009 discovery because of inconsistencies in the timeline of the crimes in the series. If that is indeed true, it begs the question, why did they not recheck the DNA against this possibility when they first suspected it?
The question is doubly potentiated when you look at the behavioral evidence in the series. There is an insane — superhuman, really — amount of criminal expertise and versatility shown in these crimes — if they are looked at in a vacuum.
One perpetrator is, of course, not the simplest explanation (the author believes greatly in Occam’s Razor). Investigators should have exercised enough controls to at least test that simplest explanation before moving forward.
The Direct Costs
Around 40 cases (including the six murders) had to restart from the ground up after the discovery of contamination. Throw in 1400 false leads, 2400 unneeded DNA checks and you get 16000 wasted hours of overtime over eight years (2001–2009).
To quantify the case monetarily, an estimated 2 million euros were wasted over the entire duration of the investigation. The money figure of course does absolutely nothing for the dozens of victims denied justice in their cases because of this colossal blunder by police. Only Officer Keisewetter’s murder would be solved — more on that in number “XV” below.
Handling Cognitive Biases
A cognitive bias is “any systematic deviation from a normative criterion that affects thinking, often leading to errors in judgment.” Consider them, essentially, bad habits that effect thinking.
We can see where a number of cognitive biases propelled this case straight into the gutter. The most obvious one at play is a version of “the Detective’s Fallacy” of tunnel vision: confirmation bias. This bias is ignoring negative information to cherry-pick data that makes your opinion look good. Investigators did this by ignoring the behavioral evidence and their hunches that maybe this was contamination until it was positively found to be that one year later.
Another bias at play is the “bandwagon effect” which is another term for “herd mentality” or “groupthink.” This may explain why those police with hunches about contamination decided not to do anything about it. Your community believing something opposite of your beliefs can be a scary thing for anyone.
These are just two of many biases that could have been at play. The only way to fight them — as they are hardwired into the human brain — is to be aware of them in ourselves and others. Cultivating an atmosphere that values pointing them out in ourselves and others is the best way to nip them in the bud.
We could make great strides in stopping this from happening again by trying to cultivate that atmosphere in our law enforcement agencies.
Officer Keisewetter and the NSU Murders
This leaves one question that can be answered regarding the crimes in the series. Who killed Officer Keisewetter and attempted to kill Officer Arnold? This is where the alt-right (before they were called “the alt-right”) enter our story.
From 2000 to 2007, the National Socialist Underground (NSU) perpetrated a series of xenophobic murders mostly targeting ethnic Turkish small business owners in Germany, but also one ethnic Greek, and Officer Michele Keisewetter because of a connection she and her family had to the group.
That is not at all to say Officer Keisewetter or her family were neo-nazis. They absolutely were not. Her dad, however, tried to rent a local bar that was a favorite hangout for the alt-right thugs. This bar had a cook with the same surname as Beate Zschäpe one of the three NSU foot soldiers responsible for the murders. After one of the longest trials in German history, Zschäpe would be sentenced to life for 10 murders in 2018.
Officer Keisewetter herself lived across from this bar from 2001 to 2003. It is thought that the NSU got paranoid after some of them believed she saw them in a meeting. Then Uwe Böhnhardt and Uwe Mundlos (Mundlos killed Böhnhardt then himself before they could be arrested) made the choice to track Officer Keisewetter down and shoot her.
The Phantom of Heilbronn stands in criminal history as one of the oddest and largest police blunders of all time, having wasted eight years of three countries’ time. Countries everywhere should learn from it, that we can make sure nothing like it ever happens again.